you selected the Desktop mode with selected area. At start the program opens a mask, the window with white transparency. Using this window, by mouse, you should select an area of Desktop where the program will capture that part of desktop. After it you press the button Close and the mask closes, the program is ready for work: You open your pictures and place them to the selected area on Desktop, the program shows them in its main window. Then you can open Screenshots and make new photos from the selected area,